This invention relates to the control of an indoor air conditioning unit having an air filtration system within the unit.
Indoor air conditioning units now include various air filtration systems which filter the air passing through the units. These air filtration systems typically require that at least a fan be activated so as to circulate air through a filter which removes impurities in the air such as dust, odors, or volatile chemical compounds. The filters that remove these impurities usually require some form of activation in order to perform their respective filtering capabilities. In the case of passive filters, this may only require the activation of a fan so as to circulate air through the filter. In the case of other types of filters such as electrostatic filters and photocatalytic filters, there may be a need to activate particular filtering mechanisms.
It is desirable that any of the aforementioned filters be appropriately activated when the air quality in a room deteriorates. It is, however, not always possible to easily read the display of conditions measured by a unit so as to thereby activate air filtration. This may be especially true for an air conditioning unit mounted relatively high on a wall wherein a remote control is often used to read the conditions measured by the unit. It is also possible that an occupant of a room being heated or cooled by the air conditioning unit would not even react to poor air quality. In this regard, the occupant may be quite aware of comfort level such as temperature but not have any idea as to air quality level. Furthermore, the air filtration system may simply not be activated when the room or space is unoccupied. While this latter situation may be appropriate for unoccupied times, there will nonetheless be a period of time before the quality of air is brought to within allowable limits following occupancy and activation of the air filtration system within the unit.
The present invention provides an air conditioning unit with an air filtration system that is automatically activated any time of the day or night when the measured air quality in a space drops below permissible limits. The around-the-clock air filtration capability is preferably an automatic mode of operation which may be selected when programming the operation of the unit. The air filtration system includes an air contaminant sensor preferably mounted within the unit in such a manner so as to be able to sense the air surrounding the unit. The air contaminant sensor is connected to a microprocessor control that has been programmed to periodically read the sensor so as to determine whether the air quality in the room has dropped to a level requiring the activation of one or more air filters in the unit. The thus activated air filters remain on until such time as the sensed contaminant level has reached a point where the air quality level is acceptable.